The present invention relates to a musical instrument and/or acoustic apparatus body part of which is to be made of polyurethane foam, more particularly to the musical instrument and/or acoustic apparatus, such as an electric guitar, a piano, an amplifier, whose casing or entire body is to be made of polyurethane foam, which has good property of moulding and processing and does not result in crack and twist.
According to the present invention, the musical instrument and/or acoustic apparatus is provided by moulding the entire body part of instrument as being one body with polyurethane foam, therefore, resulting in a period of process shorter than the prior arts which have used woods, and saving the process cost, while maintaining the quality of sounds coming from those musical instrument and/or acoustic apparatus in at least same level as those of the prior art.
The various kinds of musical instruments, such as electric guitar or piano, has customarily been made of woods which should have been selected through a rigid inspection, and therefore, was expensive. In order to manufacture the electric guitar, especially the body part of electric guitar with wood in the conventional process, the woods should be processed by baking/drying the woods in a drying furnace; sizing the wood into a predetermined size; gluing the woods together into the predetermined shape of electric guitar; and processing the body of electric guitar to provide a pocket with which the required electric devices are equipped, and to have a predetermined curve of outline, which have been complicated and long-term processes.
Moreover, in order to provide the wooden electric guitar with the optimal acoustic property, the respective conditions for each process must be varied depending on the corresponding woods, and much time and labor are required for shaving and milling wood into the desired shape of guitar. Nevertheless, since most of woods had its own defects, which is not appropriate to be used as wood source, a high percent of processed woods have been disposed. It has been a representative problem in the field of manufacturing wooden guitar.
In order to overcome this problem, some approaches have been proposed, especially by manufacturing the guitar with injection moulding of plastic resin, such as ABS, into the plate body part; and gluing the wooden neck part with the plate body part to completing the entire body part of guitar.
However, according to the above process, since only plate body part of the entire body part of guitar was moulded with resin, and neck part should be made of wood, and thereafter bounded together, those multi-step process and their costs have not been reduced in a significant scale. Furthermore, the specific gravity of resin, such as ABS resin, which was recently used, was too high to be used for manufacture of electric guitar. Moreover, after completion of manufacture steps, some phenomenon such as twist or crack was incurred on the body of guitar. Therefore, it became another problem that the acoustic quality of sound coming from the guitar manufactured by the recent prior art.
Therefore, an object of the present invention is to solve the aforementioned problems, and provide a musical instrument and/or acoustic apparatus, such as an electric guitar, a piano, an amplifier, whose casing or entire body is to be made of polyurethane foam, which has good property of moulding and processing and does not result in crack and twist.
Another object of the present invention is to provide the musical instrument and/or acoustic apparatus by moulding the entire body part of instrument as being one body with polyurethane foam, which can result in a shorten period of process shorter than those of prior arts which have used woods, and the save of process cost, while maintaining the quality of sounds coming from those musical instrument and/or acoustic apparatus in at least same level as those of the prior art.
Still another object of the present invention is to provide the casing of musical instruments and/or amplifier for electric guitar.
The present inventors have extensively and intensively studied for overcoming the problems of prior art, and found out that the above-mentioned objects can be accomplished by using polyurethane foam in stead of the plastic resin and moulding each plate body part and neck part of guitar into one-body as being the entire body part, with creating no crack or twist in the body even after the process. Furthermore, it can result in a shorten period of process shorter than those of prior arts which have used woods, and the save of process cost, while maintaining the quality of sounds coming from those musical instrument and/or acoustic apparatus in at least same level as those of the prior art.
The present invention provides a musical instrument having its entire body portion manufactured by moulding the body with synthetic resin.
According to a preferred embodiment of the present invention, a musical instrument having its entire body portion manufactured by moulding the body with synthetic resin, in which the said musical instrument is an electric guitar which has the entire body consisting of a base plate, a neck part connected to the base plate, and a head part connected to the end of the said neck part to hang the strings, and in which the said entire body is made of polyurethane foam having specific gravity in the range of 0.3 to 0.9.
According to the second embodiment of the present invention, an electric guitar having its entire body portion manufactured by moulding the body with synthetic resin is provided, in which the additional porous particles selected from a group comprising wood chips, silica or mixtures thereof are homogeneously contained in the polyurethane foam which forms the entire body portion of the electric guitar.
According to the preferable embodiment of the present invention, the amount of particles to be able to be admixed in the polyurethane foam is 5 to 8% by weight based on total weight of polyurethane foam. The average diameter of the porous particles may range from 1 to 50 xcexcm.
According to another preferred embodiment of the present invention, the said musical instrument is a piano, and in which the interior part and/or exterior part consisting the entire body of piano is made of polyurethane foam having specific gravity in the range of 0.3 to 0.9.
According to still another embodiment of the present invention, an exterior casing of amplifier for electric guitar is provided, in which the said exterior casing is made of polyurethane foam having specific gravity in the range of 0.3 to 0.9.
According to another embodiment of the present invention, an exterior casing of electric guitar for enclosing and/or protecting is provided, in which the said exterior casing is made of polyurethane foam having specific gravity in the range of 0.3 to 0.9.